It is previously known a variety of lock devices that make use of electronically controlled elements for increasing the security of the lock. However, the demand for lock systems with a high level of security is constantly increasing.
Many prior art electro-mechanical lock devices rely on a power source external to the lock device for powering the electronic circuitry of the device. This poses a problem, particularly when fitting a new electro-mechanical lock in an existing installation.
One way to avoid this problem is to provide a replaceable battery either in the lock device or in the keys used with the lock device. However, the replacement of the battery is often a cumbersome operation. Furthermore, the battery takes up valuable space, irrespectively of whether it is provided in the lock or in the key. Also, batteries constitute an environmental hazard.
Another problem with today's electro-mechanical lock devices is that they must include not only mechanical locking elements but also the electronic circuitry and elements controlled by the electronic circuitry. All these elements must fit into the space defined for conventional all mechanical locks. The size of the electronic part of the locking mechanism must therefore be kept to a minimum.
Yet another problem with prior art electro-mechanical lock devices is that when the key having correct mechanical code is inserted then all key-actuated moveable blocking elements are moved to non-blocking position; only the electro-mechanical blocking element remains to prevent the rotation of the cylinder core.